The present invention relates to a worm press for separating liquids from solids-liquid mixtures, in particular fibrous suspensions, more particularly under pressure, including a worm rotating inside a jacket comprising liquid passages, wherein the shaft of the worm which is preferably of hollow construction, comprises in the axial conveying direction following onto the region which comprises at least one worm rib, a smooth terminal region in which the worm shaft is designed as a jacket shaft, provided with a cavity between a shaft jacket and a preferably hollow shaft core, and that this shaft jacket comprises liquid passages, for example bores, leading into the aforementioned cavity, this cavity being in communication with at least one liquid drainage means.
A worm press of the aforesaid type is already known from U.S. Pat. No. 3,394,649 (Kemper et al). This worm press serves for the dewatering of sludges or cellulose pulp suspensions and comprises a hollow worm shaft having apertures at the end of the pressure zone. Through these bores still further liquid can be drained into the hollow shaft, this liquid draining inside the shaft in a direction opposite to the conveyance direction. However, such a worm press suffers from the disadvantage that only small amounts of liquid can be drained through the bores into the cavity of the shaft. Furthermore, these shafts, when employed for dewatering fibrous suspensions are very susceptible to being blocked by fibres.